I was told by a KTM dealer that the Tubliss might not work with the stock rear wheel because of its width. Tubeless list their 18" unit for rims which are 1.85" ~ 2.15". 21" unit is for rims 1.65". KTM shows stock rims to be 18" x2.50" and 21" x 1.85". Are you running stock rims? I'm looking to try these with Heidenau K60 Scout 50/50 tires or Mitas MT 07 Dakar 50/50 tires. If you can beat them up off roading and on the street, they should hold up for a long adv ride or commuting on the street. Also what tire pressure are you running when on the street?
Thanks